"In natural science the principles of truth ought to be confirmed by observations." (Linnaeus). "Though, preferably backed up by a series of high quality digital photos and video." (KerryBirding).

Click on any of the main images for a closer view

Tuesday, 25 April 2017

Some migrants at Black Rock

Purple Sandpiper, Black Rock, 25th April 2017 (David O'Connor).

Although some might describe Purple Sandpipers as a somewhat nondescript species, up close they have an exquisite and subtle patterning. But what an extraordinary bird. Lurking under that otherwise modestly-plumaged exterior is an extraordinary engine, resulting in one of the few bird species that regularly cross the Atlantic each spring and autumn.

Because they nest in the high Canadian Arctic, it is not unusual to see this species well into May in Ireland as the birds are no doubt instinctively aware, their breeding grounds are often under ice and snow well into late spring. An amazing article in the Ardea journal (see below) recently showed the remarkable migration these birds make.

Fifty geolocators attached to Purple Sandpipers wintering in northern Scotland and southwest Ireland (Co. Clare) showed that the spring departure from Scotland and Ireland took place mainly in late May and that the birds staged in Iceland and/or southwest Greenland before reaching their breeding grounds in Arctic Canada, mainly Baffin, Somerset and Devon Islands.

Map of wintering (blue) and breeding (yellow) distribution of Purple Sandpiper. Although it was thought that Irish Purple Sandpipers bred in Scandinavia, or perhaps Iceland, the truth is, they are nesting far across the Atlantic into the heart of Arctic Canda (map adapted from www.hbw.comwww.hbw.com).

The return migration from Baffin Island and Labrador took place during late October to early November, and during mid to late December from Greenland, usually in a single trans-Atlantic flight. This ties in nicely with local records from the main wintering area in Kerry - Rough Point and the Magharees - where they are scarce in October and November, but numbers quickly build in December.

No birds staged in Iceland on the return trip, instead the birds made the trip in one enormous flight. The journey from Baffin Island to Scotland and Ireland took about 2.5 days at an average speed of about 1400 km per day. That's an equivalent to us making our way, under our own steam, from Costa's Coffee Shop on The Mall, Tralee, to Costa's Coffee Shop in Madrid Airport, in one day.*

The Wheatear and White Wagtail are also certain to embark on a trans-Atlantic flight of their own. White Wagtails passing through Ireland at this time are thought to nest largely in Iceland (there is also a small outpost of breeding birds in east Greenland), and the 'Greenland Wheatear' in, well, Greenland, but also all over Iceland AND largely shares the breeding areas shown above for Purple Sandpiper in Arctic Canada.

*No sponsorship from Costa's Coffee Shop, in either Tralee or Madrid, was received for this blog post. I asked, but they just laughed in my face. Their coffee isn't all that great anyway.

Finding Birds in Ireland - Second Edition

For more information and maps of Kerry sites and many other birding sites around Ireland, see the book Finding Birds in Ireland. It can be purchased from www.gillmacmillanbooks.ie, Amazon.co.uk, or on birdwatchireland.ie.